package top.fzqblog.nullable

/**
 * Created by 抽离 on 2017/8/4 0004.
 */
fun main(args: Array<String>) {
    var a:String? = "啦啦啦"
    a = null
    val l = a?.length
    val b = a?.length ?: -1
    val c = a !!.length//不存在所以报了KotlinNullPointerException
    println("l：" + l)
    println("b：" + b)
    println("c：" + c)

}